compounds/metabolites has several advantages. For example, (i) When a plant
based drug is produced from the source like endophytic fungi, it will not only
reduce our dependence on plant sources for these metabolites but also help in
preserving the continuously decreasing plant biodiversity on earth (Strobel et al.
2004 ). (ii) Environmental conditions which affect the quality and quantity of
desired phytochemicalsin plantacan be avoided if isolated endophytes are cultured
successfully in vitro by providing optimum physicochemical parameters.
(iii) Production of plant derived drugs using microbial sources can be easily scaled
up for industrial process. It is also possible to obtain improved versions of existing
drugs by simply altering the cultural conditions. (iv) Isolation of drugs from
microbial sources is relatively easier and cost-effective as compared to extraction
and purification of drugs from the whole plant or plant part(s) including tissue
culture. (v) Since the plant and fungal endophytes, both are eukaryotic systems, the
metabolites produced by the endophytes are less likely to show mammalian toxicity
when used for human applications and, (vi) High-value metabolites/compounds of
medicinal importance are produced in easier and economical way using the
endophytic microorganisms (Strobel et al. 2004 ).
It has been proved that both plant and endophytic fungi isolated from the same
plant produced similar compounds with same bioactivity (Kusari et al. 2012 ). The
possible reason for this could be the genetic recombination between the host and
endophytes or vice versa that occurred during the course of evolution (Tan and Zou
2001 ).
In the ensuing paragraphs, an attempt has been made to briefly review the studies
on plants and endophytic fungi which could produce antioxidant, antihyperc-
holesterolemic, antidiabetic, and anticancer metabolites of therapeutic importance.
10.2 Antioxidant Activity of Plants/Plant Extracts
Reactive oxygen species (ROS) generated in the biological system are the major cause
of the degenerative conditions such as aging, cancer inflammation, atherosclerosis, etc.
(Sandesh et al. 2014 ). Naturally occurring antioxidants/enzymes, superoxide dismu-
tase, catalase, glutathione, etc., can stabilize the adverse effects of ROS and, thus help
maintain the redox balance in the body. However, when generation of ROS is more
than what can be processed by the endogenous antioxidant system, it results in
oxidative damages leading to several other disorders such as arthritis, atherosclerosis,
cancer, diabetes, and many others (Castaneda et al. 2003 ). Sufficient amounts of
exogenous antioxidants are required to reduce the effects of ROS to the human body. In
response to the growing consumer demand for food supplements that are free of
synthetic antioxidants with carcinogenic potential (Baardseth 1989 ), there has been
tremendous increase in the search for naturally occurring antioxidants during the past
decades (Gould 1995 ). Of the vast amount of literature, a concise list of studies on the
antioxidant activities of plant/plant parts using DPPH free radical scavenging assay,
mainly in last 10 years is shown in Table10.1.
10 Endophytes: Potential Source of Therapeutically... 215